DAY5：字典

无序性：

 1  # -*- coding:utf-8 -*-
 2  # Author: TanJincheng
 3  
 4  room = {
 5      "s2": "han meimei",
 6      "s1": "li lei",
 7      "s3": "zhao rui",
 8      "s4": "er gou",
 9      "s5": "liang cheng"
10  }
11  print(room)#字典是无序的
12  
13  
14  
15  >{'s2': 'han meimei', 's1': 'li lei', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}

替换：

1 room["s1"] = "wang gang"#改变字典内容s1
2 
3 >{'s2': 'han meimei', 's1': 'wang gang', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}

添加：

1 room["s6"] = "zheng liang"#搜索字典值s6，存在就改，不存在就增添
2 print(room)
3 room["s1"]="hong li"
4 print(room)
5  
6  
7 >{'s2': 'han meimei', 's1': 'li lei', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng', 's6': 'zheng liang'}
8 >{'s2': 'han meimei', 's1': 'hong li', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}

删除：

 1 del room["s1"]#删除s1
 2 print(room)
 3 room.pop("s2")#删除s2
 4 print(room)
 5 room.popitem()#随机删除
 6 print(room)
 7 
 8 
 9 
10 >{'s2': 'han meimei', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}
11 >{'s3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}
12 >{'s3': 'zhao rui', 's4': 'er gou'}

判断：

 1 >>>"s5" in room#控制台判断
 2 True
 3 
 4 
 5 
 6 >>>room.get("s2")#控制台查找
 7 'han meimei'
 8 
 9 
10 
11 
12 >>>room["s1"]#控制台查找
13 'li lei'
14 
15 
16 
17 >>>room["s7"]#控制台查不到报错
18 Traceback (most recent call last):
19   File "<input>", line 1, in <module>
20 KeyError: 's7'
21 >>>room.get("s7")#无内容
22 None

输出key值：

 1 for i in room:#输出key值
 2     
 3     print(i)
 4 
 5 
 6 
 7 
 8 >s2
 9 >s1
10 >s3
11 >s4
12 >s5

其他：

1 #values
2 >>>room.values()
3 dict_values(['han meimei', 'li lei', 'zhao rui', 'er gou', 'liang cheng'])
4 
5 
6 #key
7 >>>room.keys()
8 dict_keys(['s2', 's1', 's3', 's4', 's5'])